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Backup2l Installation And Configuration in Debian

What is backup2l ?

backup2l is a lightweight command line tool for generating, maintaining and restoring backups on a mountable file system (e. g. hard disk). The main design goals are are low maintenance effort, efficiency, transparency and robustness. In a default installation, backups are created autonomously by a cron script.

backup2l supports hierarchical differential backups with a user-specified number of levels and backups per level. With this scheme, the total number of archives that have to be stored only increases logarithmically with the number of differential backups since the last full backup. Hence, small incremental backups can be generated at short intervals while time- and space-consuming full backups are only sparsely needed.

The restore function allows to easily restore the state of the file system or arbitrary directories/files of previous points in time. The ownership and permission attributes of files and directories are correctly restored.

An integrated split-and-collect function allows to comfortably transfer all or selected archives to a set of CDs or other removable media.

All control files are stored together with the archives on the backup device, and their contents are mostly self-explaining. Hence, in the case of an emergency, a user does not only have to rely on the restore functionality of backup2l, but can - if necessary - browse the files and extract archives manually.

For deciding whether a file is new or modified, backup2l looks at its name, modification time, size, ownership and permissions. Unlike other backup tools, the i-node is not considered in order to avoid problems with non-Unix file systems like FAT32.

Download backup2l

http://sourceforge.net/projects/backup2l/

Install backup2l in debian

#apt-get install backup2l

Reading Package Lists... Done
Building Dependency Tree... Done
Suggested packages:
cdlabelgen (3.5.0-1)
The following NEW packages will be installed:
backup2l (1.4)
0 upgraded, 1 newly installed, 0 to remove and 0 not upgraded.
Need to get 29.8kB of archives.
After unpacking 143kB of additional disk space will be used.
Get:1 http://mirror.ox.ac.uk stable/main backup2l 1.4 [29.8kB]
Fetched 29.8kB in 0s (44.7kB/s)
Selecting previously deselected package backup2l.
(Reading database ... 34584 files and directories currently installed.)
Unpacking backup2l (from .../archives/backup2l_1.4_all.deb) ...
Setting up backup2l (1.4) ...

This will complete the installation.

If you want to know more options check backup2l man page

Backup2l configuration

The default configuration file is located at /etc/backup2l.conf

You need to change the some of the parameters to work for your environment

You need to enter the list of directories you want to backup under this list

# List of directories to make backups of.
# All paths MUST be absolute and start with a '/'!

SRCLIST=(/etc /root /home /var/mail /usr/local)

the above example is showing /etc /root /home /var/mail /usr/local directories are taking backup

You need to enter the list of directories you want to exclude from backup under this list

# This example skips all files and directories with a path name containing
# '.nobackup' and all .o files:
SKIPCOND=(-path "*.nobackup*" -o -name "*.o")

SKIPCOND=(-path "/var/www/domains/*/logs/*/")

the above example we are excluding /var/www/domains/*/logs/*/ folder

You need to mention the Destination directory for backups

# Destination directory for backups;
# it must exist and must not be the top-level of BACKUP_DEV

BACKUP_DIR="/home/backup"

the above example /home/backup is the destination directory

Backup Parameters list

# Backup parameters

# Number of levels of differential backups (1..9)
MAX_LEVEL=3

# Maximum number of differential backups per level (1..9)
MAX_PER_LEVEL=8

# Maximum number of full backups (1..8)
MAX_FULL=2

# For differential backups: number of generations to keep per level;
# old backups are removed such that at least GENERATIONS * MAX_PER_LEVEL
# recent versions are still available for the respective level
GENERATIONS=1

# If the following variable is 1, a check file is automatically generated
CREATE_CHECK_FILE=1

If you want to menction pre and post backup scripts you need to enter the following section

# Pre-/Post-backup functions

# This user-defined bash function is executed before a backup is made
PRE_BACKUP ()
{
echo " pre-backup: nothing to do"

# e. g., shut down some mail/db servers if their files are to be backup'ed

# On a Debian system, the following statements dump a machine-readable list of
# all installed packages to a file.
#echo " writing dpkg selections to /root/dpkg-selections.log..."
#dpkg --get-selections | diff - /root/dpkg-selections.log > /dev/null || dpkg --get-selections > /root/dpkg-selections.log
}

# This user-defined bash function is executed after a backup is made
POST_BACKUP ()
{
# e. g., restart some mail/db server if its files are to be backup'ed
echo " post-backup: nothing to do"
}

This is very useful whenevery you want to take a backup of you databases or you need to run something before starting back or after finishing backup

Now finally we need to make sure the crontab entry for backup2l

By default backup2l installation will copy a script in /etc/cron.daily folder with the file name zz-backup2l

If you want to see the file contect as follows

#vi /etc/cron.daily/zz-backup2l

#!/bin/bash

# The following command invokes 'backup2l' with the default configuration
# file (/etc/backup2l.conf).
#
# (Re)move it or this entire script if you do not want automatic backups.
#
# Redirect its output if you do not want automatic e-mails after each backup.

! which backup2l > /dev/null || nice -n 19 backup2l -b